In recent years, portable electronic devices have been developing rapidly, for example, smart electronic devices and tablet computers, etc. have been wildly used in modern people's life, and optical lenses which are installed on the portable electronic devices are also developing accordingly. With the advancement of technologies, the requirements by users on imaging quality of the optical lenses are becoming higher and higher. The optical lens of the prior art is mainly composed of a lens barrel and lenses, the lens barrel has a light aperture and thus presents a tube-like shape, the lenses are assembled in the interior of the lens barrel, during assembling, the lenses must be assembled one by one in a specific assembling sequence and then the lens group is positioned in the interior of the lens barrel via a locking ring. However, such optical lens will generate stray light therein.